Does Tesla give users any information about their journey or their driving behaviour via their account? If so, what kind of information do drivers have access to?
If you mean help with navigation and charging locations, yes.
I was thinking more along the lines of aggregate information about the driver's behaviour such as average speed of journey, braking habits, erratic driving behaviour and so.
Those are not available
The only way that it would be available is for a service to capture the live data and aggregate it themselves. The car will give up its location, direction, speed, and odometer. But they are only in 'real time' not historical.
You could capture that data and produce the type of data you are looking for. But it is not available directly from Tesla.